• Aim: How do we use radians to measure angles?

In this lesson we will watch two videos. One video will explain how we will convert an angle degree measure into radian measure. The other video will explain how to change and angle from radian measure to degree measure.

Copy down the questions below and answer them as you watch the videos. Be sure to copy the instructor's examples so you may practice.

Questions:
1. What is the unit circle?
2. How do we convert and angle from degree measure to radian measure?
3. How do we convert an angle from radian measure to degree measure?

Video 1

Video 2

Here are some videos to help you find refernece angles. This will help you find exact trig values of any angles, not just those that lie in the first quadrant. These are videos for a future lesson.

using degrees

using radians


Here's a short video to help you remember the trig values on a unit cirle

Unit Circle trick


Homework: Do all problems

8.2_Radian_Measure.JPG

Answers

A-8.2_Radian_measure.JPG


Journal entry: What is the degree measure of an angle whose radian measure is equal to 1? Would radian measure be appropriate for very fine measurements? Justify your answer.